Magnetic latches are commonly used to seal doors on cabinets, appliances, and other applications where openings and closings are frequent. A magnetic latch provides an inexpensive, durable, and simple latch device. One disadvantage of magnetic latches is the “stickiness” of the latch when attempting to first budge it from the closed position. The reason is that the magnetic force is greatest when the magnet or its strike plates are in direct contact with the metallic catch plate to which the magnet is attracted. The intensity of the magnetic field dissipates rapidly as the catch plate is moved from the magnet during the process of opening.
For a typical door, the above “stickiness” when freeing the catch plate from the magnet is a minimal problem since a person opening the door typically has ample room to grasp a handle and pull. When a person has only a small space within which to reach and grasp a handle, however, the “stickiness” of a magnetic latch can be problematic. Worse, when a person must reach under or around an apparatus in order to grasp a handle, the person may have very little leverage or room, and the ‘stickiness” of the magnetic latch may require an awkward yank on the handle rather than a smooth and comfortable pull.
It would be advantageous to combine the inexpensiveness, durability, and simplicity of a magnetic latch with an easier method of freeing the catch plate from the magnet when opening the door. This advantage would be particularly desirable in those instances when a person has little room to reach a handle and must reach under or around encumbrances in order to exert force to open the door. Such a situation exists, for example, if the latch door opens downward within a small space that is lower than the level of an adult's comfortable reach.
One embodiment of the invention is a magnetic latch mechanism for removably latching a first member to a second member, comprising: a magnet emitting a magnetic field mounted to the first member; and a magnetically attractive catch plate mounted to the second member; wherein, prior to moving one member in relation to the other member, the position of the catch plate is moved in relation to the position of the magnet from a position strongly engaged with the magnetic field to a position weakly engaged with the magnetic field.
Another embodiment of the invention is a marking device, comprising: an enclosure panel for covering a space; a frame member proximate to an edge of the space; a magnet emitting a magnetic field mounted to the frame member; and a magnetically attractive catch plate mounted to the enclosure panel; wherein, prior to moving the enclosure panel covering the space, the position of the catch plate is moved in relation to the position of the magnet from a position strongly engaged with the magnetic field to a position weakly engaged with the magnetic field.
A process for unlatching one member from a second member, comprising: mounting a magnet emitting a magnetic field to the first member; mounting a magnetically attractive catch plate to the second member; prior to changing the position of one member in relation to the other, moving the position of the catch plate in relation to the position of the magnet from a position strongly engaged with the magnetic field to a position weakly engaged with the magnetic field; and changing the position of the first member in relation to the second member.